# -*- coding: utf-8 -*-
# @Time: 2021/8/25 8:48
# @File: arg-136.py
# @DESC:
from typing import List


def singleNumber(nums: List[int]) -> int:
    while len(nums) > 1:
        # 每次将重复的两个数字移动最后
        l = len(nums)
        
        nums.pop()
    print(nums)
    print("over")


nums = [4, 1, 2, 1, 2]
r = singleNumber(nums)
print(r)
